The present invention relates to an apparatus or device for cleaning combustion chamber valves of conventional internal combustion engines.
Internal combustion engines are capable of converting a wide variety of petroleum products such as gasoline, kerosene, fuel oil, liquefied petroleum gas, and so forth into mechanical energy. Due to convenience of supply, the dominant petroleum product used for internal combustion engines is gasoline. Use of gasoline leads to combustion deposits due to inherent impurities of the petroleum product. For example, a common use of the internal combustion engine is for powering an automobile. A typical automobile utilizes a reciprocating piston, four cycle, water-cooled, poppet valve, gasoline engine. The engine may be air or water cooled and employ from one to sixteen cylinders with two or four valves per cylinder.
The valves are within the cylinder portion of the engine where a sequence or events taxes place to convert gasoline into mechanical power. Valves are used to control intake and exhaust of the cylinder while a reciprocating piston travels the length of the cylinder in conjunction with the valve operation. An intake stroke occurs when the piston performs a downward stroke while an intake valve is open. The downward motion of the piston draws an explosive mixture of gas/air past the intake valve and into the cylinder. A compression stroke occurs when the previously opened intake valve is closed and the piston rises to compress the gas/air mixture. At the upper limit of the piston movement the mixture is ignited resulting in an explosion which forces the piston downward, or power stroke. A fourth stoke, known as the exhaust stroke, utilizes an exhaust valve to expel the spent mixture from the cylinder. This sequence is commonly referred to as a four-cycle rotation.
These valves, whether sleeve, rotary, slide or poppet are subjected to explosive forces best described as brutal. Valves are momentarily exposed to a burning mixture whose temperature may approach 5000 degrees Fahrenheit. The valves, unlike the piston which is cooled by oil or the cylinder which is cooled by water, cannot readily be cooled. Cooling of the valves is usually limited to heat dissipation through the valve stem and the amount of time the time the valve is in contact with a valve seat. If the engine operates at 3000 rpm's then the valve is lifted off the seat 1500 times per minute. Valve technology includes face coatings, head coatings, aluminizing and hollow stems filled with metallic sodium to help the valve cooling operation.
Over a period of time this harsh operating environment may lead to the premature destruction of the mating surfaces between the valves and valve seats. As this mating surface degrades unburnt gases can create a residual of carbon deposits that adhere to an angular neck area of the valve located between the valve stem and valve face. Once these deposits begin the temperature bakes the deposits on accelerating the degradation of the mating surfaces until a loss of cylinder compression occurs causing the engine to run poorly.
The present invention is directed to the situation wherein the valves no longer seat correctly requiring resurfacing of the valves. During the valve refurbishing process the valve is placed on a refacing machine, however, before the valve is placed on a resurfacing machine the carbon deposits that adhered to the valve must be removed to prevent clogging of the facing wheel or additional problems if reinstalled on the engine.
Heretofore, it has been the practice of service shop repair men to scrape the excess carbon from the valve. Known removal techniques include the use of a pocket knife or other sharp object. A major problem with this technique arises from the valve manufactures use of high technology steels such martensitic, austenitic steels or superalloys for valve construction and the type of steel used is not determinable by the naked eye. A knife or other sharp object that is not specifically designed for the carbon removal process can damage the valve beyond repair. If a cutting tool is softer than the valve, the danger of the tool shattering causing risk of injury increases.
Another method of carbon removal is the insertion of the valve into a dip tank of chemical to dissolve the carbon. Since a normal eight cylinder car employs sixteen valves engine and a high performance eight cylinder engine may have thirty two valves, the practice of using a dip tank is not economical. The volume of chemical is unpredictable for each valve soaking dilutes the chemical resulting in frequent disposal of a hazardous waste. This method of carbon removal is also time consuming for the valves must sit in the solvent and depending on the strength of the solvent, remain in the dip until the carbon is dissolved. Further, valve marking is difficult when numerous valves are placed in chemical tank. The hazards to the environment and service personal are evident by chemical soaking.
Yet another practice is to use a rotating wire brush to remove the carbon deposits. Depending on the amount of carbon deposits this method can be time consuming for the carbon must be taken down by abrasion. In addition, the abrasion may break off large deposits or brush wires, either of which becomes a projectile injurious to operating personnel.
The problems of removing carbon deposits quickly and safely are those which have long plagued engine rebuilders and valve refurbishers. While extensive efforts have been made toward effectively and simply resolving this problem, no satisfactory solution has heretofore been provided. It is, therefore, to the effective resolution of this problem that the present invention is directed.